You can’t solve it because you don’t have c in the question
The power of the fan is 70 Watt.
<h3 /><h3>What is power?</h3>
Power can be defined as the rate at which energy is used. The S.I unit of power is Watt (W)
The power of the fan can be calculated using the formula below.
<h3>Formula:</h3>
- P = E/t.......................... Eqaution 1
<h3>Where:</h3>
- P = Power of the fan
- E = Energy of the fan
- t = time
From the question,
<h3>Given:</h3>
- E = 4.2 kJ = 4200 J
- t = 1 minutes = 60 seconds.
Substitute these values into equation 1
Hence, The power of the fan is 70 Watt.
Learn more about power here: brainly.com/question/3631756
Answer: B)Number 1, 3 and 5 all demonstrate non-contact forces because the magnets or electrically charged objects exert forces on each other without touching.
Explanation:
Forces which act only when the two surfaces are in contact are known as contact forces. For example: frictional force is a contact force because it acts only when the two surfaces have tendency to move or are in relative motion.
Forces which act without any contact between surfaces are non-contact forces. For example: magnetic force, gravitational force, electrical force.
Because Kennedy and Lilly have to prove that some forces are non-contact forces, they must put up examples which actually show force being exerted between two objects without they being in contact. Thus, number 1, 3 and 5 demonstrate this.
<h2>About 1 billion trillion stars</h2>
Since the universe is so big, we don't know for sure what the exact number is, but assuming an average of 100 billion stars per galaxy (which is smaller than a universe), we could say that there are 1 billion trillion stars in the observable universe.
